Friday, August 05, 2005

100th Post/Evolution

This, according to the blogger statistics, is my 100th post on this blog. I didn't want my 100th post to just be an announcement of my 100th post though, so i decided to write about something that i have a strong interest in: evolution.

In the same way that most evolution proponents tend to stereotype creationists as uneducated, Bible-thumping yokels who only leave the house long enough to go to church or attend NASCAR events, i suspect that creationists imagine that evolutionists spring fully-formed from the heads of East-coast leftist academics. In other words, it's hard to imagine a proper church-educated person falling for the evolution dogma. I, however, spent most of my formative years in a Lutheran parochial school (Missouri-synod Lutheran, which is to Lutheranism what Hasidism is to Judaism). Although we were not taught strict Biblical literalism (Lutherans are smart enough to appreciate a good metaphor), i was taught that evolutionary theory was incorrect and that the Biblical account of creation was correct. When i began my freshman year at the public high school, i proudly declared in my biology class that i believed that God had created the earth and all of its creatures in a week. In other words, at the fairly advanced age of 14 i was a creationist.

Although i can't remember exactly how or when my opinions began to change, i'm fairly sure that my formal high school education had little part in it. Our high school solved the debate over teaching evolution vs. creation by not teaching either. We dissected frogs and made papier mache models of cell organelles. I was aware of Darwin, and at some point either late in high school or early in college, i bought a hard-bound version of The Origin of Species, which i actually read though i recall it to be the single most boring volume i've ever slogged through.

But in high school i was a pretty hard-core science freak, and it's hard to delve into physics and chemistry without finding in the same sources discussions of natural selection, neo-Darwinism, punctuated equilibrium, etc.; not to mention the cosmological origins of the universe and genetics. By the time i started college i was pretty familiar with the ideas of biological evolution, though i was still in the "just a theory" camp (i apparently had an incorrect notion of what a theory was).

By my second or third year of college i was already a budding secular humanist (more proof of the pernicious effect of those damned liberal academics). But i wasn't really convinced about evolution. There are certain limits on human intelligence (for even the most brilliant) that make evolutionary theory hard to grasp. The first is that humans simply have no capacity to understand long time frames (Richard Dawkins discusses this in, i think, The Blind Watchmaker). Our brains are conditioned to think of 100 years as being an eternity, while all of the interesting things that happen in biological evolution require hundreds or thousands of generations. We just can't understand how long a million years is. The second limitation is the intuitive way in which we think of randomness. We have this sense that evolution involves randomness, but we know that the pure combinatorial possibilities in the human genome are so vast that the odds of getting a better combination seem remote. But DNA is not shuffled like a deck of cards. It changes slowly and subtly in most cases, and even then most mutations are selected against. But don't get me wrong. These are not hard ideas to get past just for the uneducated or unwilling; they're hard period. Unless you can convince yourself that the mechanisms of biological evolution could work, you'll never fully accept the theory. It's like having to learn quantum mechanics before you can explain why grass is green.

I think this is where concepts like Intelligent Design (ID) become so appealing. Even if you accept that the earth is billions of years old and that the planet has changed drastically over time, it's still comforting to interject some miraculous process that explains away the stuff that's almost incomprehensible. I know it was extremely hard for me to come to grips with certain aspects of natural selection. Not surprisingly in my case, what finally convinced me was writing a computer program (not surprising for me because i always understand ideas better if i can express them as programs). I was in college during the time that AK Dewdney was writing his Computer Recreations column in Scientific American, probably my favorite column ever. One of his columns was about something he called "flibs", short for finite living blobs. Flibs were a very simple form of artificial life, or a genetic algorithm, or both. Basically flibs were simple finite state machines, consisting of a string of bits. Flibs lived in an "environment", which was also a string of bits, though longer. The fitness of a flib within the environment was based on how the flib state machine responded to the environment string.

The initial set of flibs was created randomly, but at each stage the flibs that scored the best against the environment were "bred" using crossover breeding. In some cases this lead to new flibs that responded better to the environment, sometimes it didn't. The other crucial element to the flibs algorithm was in the introduction of periodic random point mutations. Without the mutations, the algorithm would tend to converge to a "best" flib and then never get better.

The flibs program is an extremely primitive approximation to biological evolution, but it taught me a couple of things. The most important aspect was probably that you could run through hundreds of generations very quickly so it did give you the sense of watching evolution unfold. The program also revealed the idea that mutations were extremely important to the evolutionary process. But the real epiphany for me was in the way that new flibs that showed greater adaptability to the environment would quickly overwhelm less fit flibs. Of course, this is based on the idea that the more fit flibs get the chance to breed most frequently and so pass on more of their genome to the next generation, but that's one of the basic assumptions of natural selection. What this taught me is that "fitness" is not a measure of some abstract ideal that human beings might strive to attain. Fitness is simply how well you pass on your genes to the next generation. In other words, there is no "goal" in evolution, no requirement that genotypical changes lead to phenotypical changes that correspond to greater strength, or size, or beauty, or intelligence.

Evolutionists themselves have, i think, muddled some of the ideas of evolution through the use of poor language. For example, it's still conventional to say that animals "adapt" to their environment, as though there's some sort of Lamarckian process whereby creatures change to better fit the environment. What really happens is that animals less adapted to their environment die, or get displaced, or fail to reproduce in numbers sufficient to sustain their population. Perhaps ID proponents would be less enthusiastic about their position if it were clear just how pitiless nature is; that nature in fact doesn't care at all about its creatures, it has no plan for them.

I won't make any attempt to address any of the scientific objections of ID-ers or creationists to evolutionary theory, because that's been done elsewhere effectively and honestly most of the objections are silly. But one argument that creationists will use is the "what are the evolutionists afraid of?" argument. They argue that if the ideas of evolution are sound, then they should be able to withstand competition. To be honest, i don't think most evolutionists would mind Biblical creationism being taught in schools, any more than we'd object to teaching Hindu creation myths, or Greek, or Hopi. Our objection is to the teaching of creationism as science, because it doesn't meet the criteria of science. Giving creationism equal time in science class would be equivalent to giving Holocaust revisionists equal time in history class.

Although both sides of the debate argue a lot of fine points, i think the fundamental issue in creation vs. evolution arguments is this: accepting biological evolution as the basis for the origin of species is the first step toward atheism. That's not to say that all evolutionists are atheists-- far from it. In fact, Pope John Paul II made his famous statement that evolution had to be regarded as more than a hypothesis (although there are indications that the Catholic church hopes to back away from that stand). Although evolutionists don't really discuss it often, i think it's true: acceptance of evolution does lead to atheism. Again, i think Richard Dawkins made this point in one of this books, but a scientific explanation for the origin of species (and essentially, life itself) is a practical prerequisite for rejecting God, even if Enlightenment philosophers did not require it.